Colorful patches on concretes, tree root and trunks, soils and rocks, in most cases, are due to the presence of algae belonging to the genera Trentepohlia and Printzina. In Malaysia not much information is available on the ubiquitous and often taken for granted organisms. This book provides information on their taxonomy and biodiversity on the algae. Description of each species is accompanied by notes on the identification detail diagrams and colored photographs to demonstrate morphological variations. SEM micrographs are included for some species. Those who wish to identify the Malaysian species of Trentepohlia and Printzina will find this book helpful as identification keys are also provided.